I have a group of users with accounts on a Community Server 2008.5 installation, and I would like them to be able to log in on that site and automatically be logged into a Drupal installation as well (on a separate machine).
I believe I'll be able to figure out the Drupal site using the many external authorization tutorials, but I haven't been able to find any information about the CS 2008.5 side of it. Does anyone have any ideas?
On
CS2008.5 can integrates easily with Microsoft Active Directory as .NET application.
So for drupal you can use LDAP integration - it's for connecting users via Active Directory:
http://drupal.org/project/ldap_integration
If there's already users in AD, and you want to add them automatically to drupal, you need to import them to via http://drupal.org/project/ldap_provisioning
There is a single sign-on module that enables authenication across sites, this is an add-on. We have used on asp.net forms authentication, but it looks like you its possible using cookies: http://telligent.com/support//communityserver/community_server_2008/w/cs20085docs/installing-cookie-authentication-extension.aspx